View and Convert your CSV, KMZ, GPX, GeoJson, TopoJson to KML What is KML? KML stands for the keyhole markup language. KML is a file format that shows geographical data in the earth browser such as google earth. KML is a tag-based structure and with the nested elements and structure and based on the XML standard. All tags are case-sensitive and this tags reference depends on the KML file. It includes line, polygon, images. It is used to identify label location, find a camera angle, overlay te